While solid state light sources (e.g., light emitting diodes, LEDs) may generate less thermal energy compared to traditional bulbs (e.g., incandescent light bulbs), solid state light sources nevertheless generate thermal energy which should be managed in order to control the junction temperature. A higher junction temperature generally correlates to lower light output, lower luminaire efficiency, and/or reduced life expectancy.
Many solid state illumination systems include heat sinks designed to dissipate thermal energy away from the solid state light source in order to manage the junction temperature. Examples of heat sinks include, for example, U.S. Pat. No. 7,592,695 (Reis et al.), U.S. Pat. No. 6,367,152 (Kataoka), U.S. Pat. No. 7,311,140 (McCullough), and U.S. Patent Pub. No. 2001/0259570 (Suzuki). Heat sinks also exist that include a copper insert coupled to an aluminum portion. The copper insert may be bolted onto the aluminum portion. A thermal paste is believed to be required to fill in the microscopic gaps between the copper and the aluminum portions, thereby creating an additional thermal interface. Copper/aluminum heat sinks also exist which include a copper insert that appears to be seamlessly coupled to an aluminum portion.